I spoke to the guys that did that project and went to a presentation by them . . .

In terms of underwater 3D slam using sonar, its very amazing. It has like 30+ sonar (if I remember right), and spins as it travels. It needs to spin to get good 3D 360 degree sonar data. Probably the perfect technology to map sink holes.

But the vehicle is horribly slow and lacks good controllability. If I remember right, it goes at half a knot full speed (yet sea current is like 2 knots+). They were trying to market it as the vehicle to explore Europa, but I think its just too slow and inefficient . . .